Assessment of the marginal mandibular nerve function after Risdon approach

Abstract

Detailed knowledge of the anatomy of the facial nerve and its branches, especially the marginal mandibular, is of fundamental importance in surgical treatment of mandibular fractures by making use of the Risdon surgical approach, avoiding possible injury which may lead to partial or total incapacity of the motor function. The aim of this study is to evaluate the function of the marginal mandibular branch of facial nerve after surgical treatment of mandibular fractures by access type Risdon. 44 patients with fractures of the mandibular body and angle, and the marginal mandibular nerve function being analyzed through visual inspection based on the rating scale in House-Brackmann facial nerve, in the preoperative and postoperatively (24 h). Patients who had some degree of dysfunction within 24 h were reassessed during 01 week, 01 month and 03 months postoperatively. Of all patients studied, thirteen (29.55%) had some degree of dysfunction in a postoperative day and thirty one (70.45%) patients had normal function at that time, being females the most affected ones (71.43%). At the end of the third month, 91% of patients had grade I (normal) on the rating scale, and 9% had grade II (mild dysfunction). Thus we can conclude that the majority of patients tested showed normal function of the marginal mandibular nerve at all times postoperatively, with mild dysfunction found most frequently and at the end of the study, patients who still had dysfunction, this one was showed in a milder degree, demonstrating safety in the Risdon approaches performed.